Without humidification, many enclosed buildings experience undesirably low humidity levels, especially during the heating season. This is due in part to the low humidity ratios of outdoor air supplied to widely-used forced air heating systems, as well as the electrically resistive heating systems found in many hotel, office, and commercial buildings. Significant problems are associated with low humidity environments, including aggravation of existing respiratory problems, and an undesirably high static electricity buildup in carpeting, other room furnishings, and clothing. It is well known that conditioned air should be humidified within a relatively narrow humidity range to achieve an acceptable human comfort level at a particular temperature and atmospheric pressure. It is also well known that uncontrolled discharge of such static electricity buildup may result in significant damage to electronic equipment such as computers and their storage and operating components.
Some forced air heating systems include the type of humidifier which admits steam directly into the supply airstream and the resulting conditioned airflow is then delivered through a supply air duct to a supply air register in selected rooms in the building. However, not all buildings or rooms are so equipped, and in those buildings that are, the heating system humidifier may be incorrectly set to too low a humidity ratio or otherwise nonfunctional. Alternatively, many buildings provide zoned or local heating systems which have no provision for an integrated humidifier.
In particular, many hotel and motel rooms are provided with individual forced air heating systems or resistive-type electrical heaters, both types of heating systems generally operating without a humidifier. Some of these systems have a through-the-wall configuration extending into the room with a horizontal top-surface air register, while other systems are integrated into the wall and discharge an air flow through a vertical air register.
Heretofore, a compact, relatively portable humidifier for use under such conditions, and especially for use by itinerant occupants, has not been successfully achieved. For example, a water evaporator disclosed in U.S. Pat. No. 435,095 provides an open water receptacle detachably affixed by a pair of brackets to the reticulated grill of a hot air register. With one end of a wicking cloth being submerged in the water receptacle, the remaining length of the cloth is suspended from a suspension rod extending above the water receptacle.
Another evaporator disclosed in U.S. Pat. No. 835,542 provides an open water receptacle similar to that of U.S. Pat. No. 435,095, further including a roller mechanism used to suspend, extend, and retract a wicking cloth overhanging the front side of the water receptacle. An important problem common to both approaches is that there is a great variety of hot air register grill configurations with vertical and horizontal orientations, many of which are not designed to accommodate the brackets of these apparatus. Another important problem is that the configuration of the water receptacles and brackets affixed thereto is relatively large and cumbersome, thereby creating a strong disincentive to portability and use by most travelers.